Geoscience Reference
In-Depth Information
Chapter 2
Geo-spatial Variability of Physiographic
Parameters and Landslide Potentiality
Abstract The stability of mountain slope depends upon physical and chemical
properties of the soil. In the present work geomorphic properties such as slope
angle, slope aspect, slope curvature, lithological composition, and lineament as well
as behaviour of slope materials such as texture, cohesion (c), friction angle (
),
water holding capacity, porosity, weight soil density and density of soil water were
assessed and found out the relationship with landslip in the Shivkhola Watershed.
Slope angle, slope aspect and slope curvature were derived from DEM on GIS
platform. Lineament map was prepared using Satellite Image LISS III (2010). Soil
samples were collected from 50 different locations and their laboratory test were
being carried out to assess cohesion, friction angle, water holding capacity, pore
space, and wet soil density. The spatial distribution of the mentioned characteristics
of slope forming materials is done using ARC GIS Software. To estimate evolu-
tionary stage through which the Shivkhola Watershed is passing, hypsometric
analysis was made. Integration between landslides inventory map and derived
thematic geomorphic maps was done to assess the spatial distribution of landslide
potentiality.
φ
Keywords Slope instability
Geomorphic parameters
Friction angle (
φ
) soil
texture
Cohesion (c) porosity and water holding capacity
Volumetric expan-
sion
Wet soil density
Remote sensing and GIS
2.1 Introduction
As the form of a slope is the end product of past geological processes, the
morphological history of the slope must also be understood. Each and every
spatial segment of the earth surface possesses some physiographic aspects and the
analysis of all the aspects enables us to predict an interrelationship between
physical and cultural phenomena and as a whole. The study area, Shivkhola
Watershed comprises a number of diversi
ed physical aspects and there is a great
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